Pd-Catalyzed Four-Component Sequential Reaction Delivers a Modular Fluorophore Platform for Cell Imaging

A Pd-catalyzed cascade reaction of four versatile privileged synthons is described. The sequential reaction involves the formation of five new chemical bonds by concatenating three distinct chemical steps. One of the derivatives exhibited absorption in the visible region, fluorescence with a high quantum yield, and excellent photostability. Its application is explored in live cell imaging, which exhibited cytoplasmic and mitochondrial specific staining with no toxicity.